The Hope Credit--money for tuition and related expenses--can now be claimed for four years of college instead of just the first two, including the cost of course materials. The newly named American Opportunity tax credit lets you claim up to $2,500 per student, but starts phasing out with an income of $80,000 for singles and $160,000 for marrieds.
Also, don't forget to withhold the interest you're paying on student loans, although that deduction starts to disappear at $60,000 for singles and $120,000 for marrieds. Generally, if you paid more than $600 in interest to a financial institution, you'll get a 1098-E form as documentation. If you didn't, call the company servicing your loan and ask how much interest you paid in 2009.